[NPUW] Update NPUW AoT caching docs (#31628)

Co-authored-by: Tatiana Savina <[email protected]>

Author: smirnov-alexey

docs/articles_en/openvino-workflow-generative/inference-with-genai/inference-with-genai-on-npu.rst

@@ -289,6 +289,7 @@ Specifying ``EXPORT_BLOB`` and ``BLOB_PATH`` parameters works similarly to ``CAC
 * To export a blob with weights you need to pass ``"CACHE_MODE" : "OPTIMIZE_SPEED"`` in the config.
 * If the blob is exported as weightless you also need to either provide
   ``"WEIGHTS_PATH" : "path\\to\\original\\model.bin"`` or ``"MODEL_PTR" : original ov::Model object``.
+* Ahead-of-time import in weightless mode has been optimized to consume less memory than during regular compilation or using ``CACHE_DIR``.
 
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